(Adapted from Applicant's Abstract): This core will have three functions: 1) Interface the Program with the well established and highly successful, Transgenic and Gene Targeting Facility available at the Albert Einstein College of Medicine. In this facility transgenic mice will be generated with DNA constructs supplied by Core B. This function will be mainly to provide assistance to investigators in the labeling, identification and record keeping of the founders and their future generations. 2) Identify founders expressing the desired hemoglobins or red cell transporters, characterize them and provide assistance with breeding strategies of the founders. These include, breeding them to the transgenic mice expressing alphaH BetaS, the alpha-knockout, the Beta-knockouts, or to other transgenic and knockout lines available. 3) Breed transgenic mice which will be identified and characterized for use in Project 1 (Two animal models of organ damage in sickle cell disease); Project 2 (Transgenic expressing HbC and HbS and HbC simultaneously; Project 6 (Transgenic mice expression human K:C1 co-transport).